European patent No. 208,311 teaches how to obtain cyclohexanone-oxime in the liquid phase from cyclohexanone, ammonia and hydrogen peroxide. In the presence of a catalyst consisting of a crystalline compound having a zeolitic structure; this structure, however, requires a treatment of the silicon compounds and of the titanium compounds with proper organic compounds, which are known as templating agents (in particular tetraalkyl-ammonium hydroxides or salts thereof) and which can be synthesized only with extreme difficulty; sometimes the silicon and/or titanium source consisted of an amorphous solid material (See European patent No. 299,430 and European patent application No. 88/116,870), but the treatment with templating agents was nevertheless assumed to be unavoidable for obtaining a catalytically active structure. The preparation of said crystalline structure required a very long operative (residence) time and the use of high temperatures and pressures; furthermore, it was necessary to submit the catalyst to complex post-treatments.
The Applicant has now found that the synthesis of the oximes (starting from carbonyl compounds, H.sub.2 O.sub.2 and NH.sub.3) can be promoted also by catalysts, based on titanium and silicon, which do not exhibit said zeolitic structure and which can be prepared without any use of templating agents in a very short time.